Process for the recovery of metals from ores and the like.



UNITED STATE CHARLES S. VADNER, OF SALT LAKE CITY, UTAH.

PROCESS FOR. THE RECOVERY OF METALS FROM ORES AND LIKE.

No Drawing.

To all whom it may concern:

Be it known that I, CHARLES S. VADNER, a

-1'ious products that are finally rejected as slag or otherwise in varioussmelting operations and the'possibllity of working large deposits of lowgrade copper ores containing more or less iron, together with little or no silver and gold, provided some physical assistance or financial reimbursement coiild in some way finally be derived from such a resmelting concerns throughout the United States, and that such iron is finally thrown" away in the form of a slag containing be-- sides the necessary iron purchased either in the form of scrap or as h1gh grade iron ore, some little copper, sllver, zinc, possibly a very little gold and in ,case of lead smelters a small percentage of lead; other 'metals such as arsenic, cadmium, bismuth, etc, may also be i'hund, .so that any percentage of recovery of the above named metals that could be made at a profit either from slag dump,

as above rmrntioned, or from low grade ores containing copper and iron and possibly some 'ther values, would necessarily be worth of n'ietallurgical attention.

Th7, fact that it is proposed to treat slag dumps and low grade copper or copper iron ileposits-material, in fact, that thus far has been rejected or'thought impossible to utilize, cessarily means, that ways and means he etoi'ore unknown or unused must be appl ed or such ways and means must be used in combination with the reclamation or I til ization of waste products that have hereofore been permitted to go to waste, whether such wasteproducts were merely a source of waste, that no'method was known whereby a saving of same oould'be made at a financial profit and no further damage'was sustained by its loss, or whether said waste, besides being a loss in itself, inflicted serious incon- Specification of Letters Patent.

venience and damage upon the person and property of unwilling victims. Special reference is made to the emission of sulfurous gases from various smelting operations and the financial losses that are being sustained both by the s neltcrs in question, who are permitting these noxious gases to escape, and by the unwilling victims in attempting to defend themselves and their property. Wherefore, I propose utilizing the sulfurous Patented July 13, 1915. Application filed August 7, 1914. Serial No. 855,713.

gases emittedi'rom smelting works or any industry that produces sulfurous gases or even the production of sulfurous gases by burning sulfur orotherwise, for the reclamation of iron from slag dumps or other ores, as may be. I do not merely wish to limit myself to the recovery of iron, as other metals are found associated more or less with iron such as gold, silver, copper, lead, bismuth, cadmium, arsenic, antimony, zinc, lime; in fact. all the. present known metals that can be recovered by the proposed process and the. recovery of which would be a source of profit in addition to the objective ends of the applicatirm of the process.

Suitably pulverized mineral matter and the like, containing gold, silver, lead, bismuth, cadmium and antimony, are exposed to the. action of sulfurous gases in the presence of moisture. The reaction that takes place can be hastened byaltilizing the heat in hot slag, that contained in hot sulfurous fumes or by heat that may be artificially generated. The suitably pul verizcd slags and ores are preferably showered or sprayed down towers up which the said gases are made to pass, or otherwise exposed to the solvent action of said sulfurous gases in the presence oi beat and moisture a sufliciently long period of time for the purpose of effecting the solution of the metal and metals that it is desired to extract. This operation can be performed over a sump, so that the solvent action can be prolonged until the desired results are obtained, any method of 'iau'rying on this operation as will best suit in each particular case will necessarily be installed. In certain instances, particularly where copper, zinc, silver and gold are sought to be extracted, the addition of soluble chlorids,

one or more, the presence of which favors the solution of the above enumerated metals I in the sulfurous solution, either by their own solvcnt'powers or due to their presence in preventing secondary reactions from taking place that would tend to render the operation of the process more expensive, or in some cases, prohibitive, is desirable, and when found to be necessary, is made. I would not desire to limit myself to the above enumerated metals, but would use a solution of the soluble chlorids containing at least one of the common ehlorids capable of reacting with the metals, such as sodium ehlorid, magnesium chlorid, calcium chlorid, ferrous and ferric chlorid andcuprous and cupic ehlorid in operating the process either in the vconnfiencement of same or at any state where the soluble chlorids mentioned above, is separated from the insoluble residue by decantatlon or filtration into suitable containers and the excess of sulfurous gases are gotten rid of, either by heat, steam or air, and the surplus acidity of the solution due to acid salts, free acid or otherwise, neutralized partially or wholly, as may be necessary, with the carbonates, oxids or hydrates of calcium, magnesium, sodium, potassium or with a mixture of same, as may be possible.

Wheuiron is present, the solution is par- "tially neutralized and oxidized or not, as

desired, with air, ehlorin or any other suitable oxidizing agent. The solution, hot or cold, is then exposed in any suitable manner to the. action of air or oxygen; the iron con- .tained in said solution can thus be partially or wholly precipitated as a brownish red pulverulent powder Fell, (ferric oxid), at will by the operator, simply by regulating: 1st, the acidity of the solution; 2nd, the

- length of time of the treatment of the solution with air or oxygen; 3rd, the degree of strength of the solution of the soluble chlorids, especially while using sodium chlorid, calcium chlorid or a mixture of the soluble chlorids; 4th, the temperature of the solution; 0th, the condition of the iron after itn has been leached outof the ore and while in the leaching medium. Thus,

The neutralizing agent added takes no part in the reaction, merely reducing the acidity of the'solution thus:

Freshly precipitated ferric oxid is soluble in moderately strong acid solution, hence the necessity of reducing the acidity in order to obtain the precipitate. v

In case that the ores used contain arsenic and it is desired to eliminate and recover the arsenic, a different form of precipitating the iron is used. The solution of the ore is effected and the excess of SO is gotten rid of as above mentioned and the solution is oxidized or not, as may be desired, by a. suitable oxidizing agent and the iron is, precipitated as ferric hydrate Fe,(OH), by the addition of a sufficient amount of new tralizing agent or agents (or a combination of same) such as theoxids, carbonates or hydrates of barium, calcium, strontium, magnesium, sodium, potassium or a mixture of same can also be used. \Vhen .the iron is preci itated in this form, the ferric hydrate Fe, H) formed has the power of uniting with the arsen c present and forming eitlier ferric arsenite or ferric arscnate, as may be,

which is precipitated and removed by filtraa tion and other suitable ways from thesolm tion. Antimony, silver, gold, lead, bismuth, cadmium and other known metals that would be found dissolved in such a solution,

depending of course on the contents of the ore and ores being treated, can be precipitated as above described and recovered if found to be desirable. This method of eliminating and purifying the solution of any and all undesirable metals as aforementioned, can be used, whether the iron is eliminated and recovered by the first or'secoud mentioned method, and also when a combination of the two methods is necessary to effect an elimination of the above mentioned metals for the purpose of purifying the. solution. It is well understood that any and all steps in this HOCOSS can be carried out in the presence of heater cold, as may be most advantageous. Copper can also be eliminated by passing the solution, hot or cold, in'any suitable manner over metallic iron, The condition of the solution as to the amount of free acid and state of oxidization can be regulated to suit the best purpose of the application of the process. The copper and silver can also be precipitated as a basic carbonate by the suitably pulverized carbonatesof the alkalis. alkaline earth or a mixtureof same with or without the use of air and in the cold. i

The precipitate is separated by filtration and other suitable means and the copper, s1lver and other contained metals as may be are recovered by electrolyzing the hot or cold solution, in suitable containers. The excess acidity of the solution, dueto the decomposition of the sulfites, is gotten ridof both by heat and also by the carbonates of the metals, alkalis, alkaline earths or a mixture of same used innaffeeting the precipitation of the copper. Sulfites are formed which may precipitate out of the solution and which can be separated. and S gas and their valuable basic contents recovered therefrom. A current of air will also assist in reducing the acidity of the'solution. The formation of calcium sulfate due to oxidation is effec tive in reducing said acidity, and any such sulfate formed can be separated and recovered for use. i

It is my intention of effecting the functioning of this process for the purpose of eheapness of operation by 1st, using SO gas and water; 2nd, using SO, gas, water and heat; 3rd, using SO gas, water and a soluble chlorid or a mixture of soluble chlorids as aforemcntioned, along with heat when necessary; or using the above means in part, together or in combination, also using the soluble chlorids mentioned in part. together or in combination for. the purpose of extracting the metals aforcn'ientioned. The strength of thesolution in soluble chlorids will vary from 5% to as may be. The solution being freed from the aforementioned metals as may be and in the manner described for the best purpose of the application of the process. the zinc is precipitated from the cold solution by the means of the suitably pulverized neutralizing agent such as OXldS, ciu-bonates, hydrates, or barium, calcium, strontium, magnesium, sodium, potassium, a mixtureof same can be used, and the basic precipitate of zinc is separated by" filtration or otherwise and calcined to the oXid, smelt'ed or dissolved in any suitable manner in a solutlon-of S0 and water with or without heat and electrolyzed in any-suitable manner, whereby the zinc is recovered in metallic form.

The precautions for the removal of the acidity of the solution and recoveries of the by-products, as in the elimination of copper, should be duly observed.

Copper, arsenic, antimony, bismuth, lead;

conditionsl the solution can be hot or cold. The precipitated metals are eliminated, lhe hot solution is neutralized as beforemcm tioned. air is passed through and zinc is precipitated as a basic compound and under these conditions is termed prccipitable metal.

(opper can be precipitated froma cold sullite solution containing connnon soluble chlorids as aforementioned, as a basic com pound. by passing air through the solution,

and would be termed precipit-able metal under this condition.

The S0, is eliminated as beforementioned and re-used, along with water, or with barrcn solution. in regcnerating the. solution for the leaching of more ore and repeating the cycle of solution. precipitation and regeneration, until the metallic contents of the ore is sulliciently exhausted.

lu treating various ores it is found that same are not made up of one metal. but contain generally several ditlcrcnt metals. Thus, zinc ores will often contain copper, iron silver and other metals. ln cases where ores carry silver and copper, the copper in a sullite solution will be a source of great annoyance and loss due to the forumtion of the red precipitate cuprose cupric sulfite This the product of -a secondary reaction \vhich takes place from the decomposition of the easily decomposed cuprous sullite (.u. .h'(),, and unless this secondary reaction is overcome, the leaching of ores containing copper is ii'npractical.

The addition of soluble chlorids such as sodium chlorid, potassium chlorid others, due to their presence and their solvent action on copper salts in general, prevents the formation of the red copper precipitate above referred to, so that in this manner, the treatment of ores by the use of St) gas and water where they contain copper, which would become a failure, can,

by the use of soluble chlorids be success fully made use of. By ay of exemplilication, take an orc carrying a small amount of copper and iron. some silver and. gold. If the iro'n is found in the or! as siderite then Fe(.(),,+S()Q+3II ()+X(NaCl.nip):

resoanipx(Nam. a .)-+(io.

\Vhatcver may be the form in which the copper is combined in the ore, provided it is soluble, the final result will be cuprous sulfite Cu,S(),,, thus taking blue copper arbonate-lasurite (as orthocarbonat'e) From this'solution no red precipitate of andtreating the mineral matter with smelter ,fumes and the like containing sulfurous gases in the presence of a solution contain ing at least one of the common chlorids leaching out the metals from the mineral matter, eliminating excess-SO gas by suitable means, passing air through the'solution thereby precipitating iron, eliminating and recovering the iron.

2. A process for extracting metals from mineral matter and the like consisting in treating the mineral matter with smelter fumes and the like containing sulfurous gases in' the presence of a solution containing at least one of the common chlorids leaching out the metals from the mineral matter, eliminating excess SO 'as by suitable means, partially neutralizing the solution with a suitable neutralizing agent; passing air through the solution thereby precipitating iron as ferric oxid.

3. A process for extracting metals from mineral matter and the like consisting in treating the mineral matter with smelter fumes and the like containing sulfurous gases in the presence of a solution containing at least one of the common chlorids leaching out the metals 'froin the mineral matter, eliminating excess SO gas by suitable means, partially neutralizing the solution with a suitable neutralizing agent; pass ing air through the solution, thereby partially precipitating the iron as ferric oxid, adding sufiicient additional neutralizing agent whereby the passage of more air through the solution completely precipitates the iron as ferric oxid.

4. A process for extracting metals from 'mineral matter and the like consisting in treating the mineral matter with smelter fumes and the like containing sulfurous gases in the. presence of a solution containing at least one of the common chlorids leaching out the metals from the mineral matter, eliminating excess SO gas by suitable means, partially neutralizing the solution with a suitable neutralizing agent; passing air through the solution, thereby partially precipitating the iron as ferric oxid, adding sufiicient additional neutralizing agent whereby the passage of more air through the'solution completely precipitates the iron as ferric oxid, eliminating the ferric oxid and recovering the iron. 1

5. A processfor extracting metals from mineral matter and the like consisting in treating the mineral matter with smelter fumes and the like containing sulfurous gases in the presence of a solution containing at least'one of the common chlorids, leaching out the metals from the mineral matter, eliminating excess SO gas by suitable means, sniiiciently' neutralizing the'gsolution with a suitable neutralizing agent,

passing air through the solution thereby' precipitating the iron as ferric oxid, eliminating same, precipitating by means of iron precipitable metals such as copper, silver and others.

6. A process for extracting metals from mineral matter and the like consisting in treating the mineral matter With smelter fumes and the like containing sulfurous gases in the presence of a solution containing at least one of the common chlorids leaching out the metals from the mineral matter, eliminating excess SO gas by suitable means, sufliciently neutralizing the solution, passing air through same, thereby precipitating the iron eliminating same, precipitating'by means of iron, precipitable metals such as e0pper,sil

ver and others, eliminating same, adding sufficient additional neutralizing agent whereby passing air through the solution in the cold precipitates the iron, eliminating same, adding the carbonate of a metal and passing air through the hot solution whereby the zinc is precipitated.

7. A process for extracting metals from mineral matter and the like consisting in treating the mineral matter with smelter fumes and the like containing sulfurous gases in the presence of a solution containing at least one of the common chlorids leaching out the metals from the mineral matter, precipitating precipitable metals by means of iron, such as copper, gold, silver, lead and others whose sulfidsare insoluble in an acid solution, suflioiently neutralizing the solution with a suitable neutralizing agent passing air through in the cold, thereby precipitating the iron, eliminating same, adding the carbonate of a metal to the heated solution passing more air through same,

fumes and the like containing sulfurous' gases in the presence of a'solution containmg at least one of the common chlorids leaching out the metals from the mineral 1,146,373 &

{hatter eliminating excess of SO; gasby pass- In Witness whereof I have hereunto set air through the solution, the quantity my hand this 3rd day of August 1914 in the be ng such that the treating 0f the solution presence of two subscribing witnesses.

by iron will precipitate the metallic com- CHARLES S. VADNER; 5 pound of recipitable metals such as copper, Witnesses:

silver, go (1 and others, eliminating and. re- C. L. HANSEN,

covering the precipitable metals. E. 0. EVANS. 

